Telemeter.



A. KNIG. TELEMETBB.

APPLICATION IILED JAI. 4, 1909.

`1,000,609. v Patnted Agfl, 1911.

II/ n UNITED sTATEs PATENT oEEIoE.

ALBERT RNIG, or JENA, GERMANY, ASSIGNoR 'ro THE FIRM or cARL zEIss, or JENA",

GERMANY.

TELEEETER.

Specification of Letters Patent.

Application led January 4, 1909. Serial No. 470,596. 4

Patented Aug. 15, 1911.

To all 'whom it may concern:

Be it known that I, ALBERT KNIG, a citizen of the German Empire, and residing at Carl-Zeiss strasse, Jena, in the Grand Duchy of SaXe-IVeimar, Germany, have invented a new and useful Telemeter, of which the following is a specification.

The invention relates to stereoscopic telemeters` traveling mark telemeters as well as fixed scale telemeters. Its object is to give each of the two telescopes of such atelem eter the advantageous property, that all of its optical parts, not only those lying behind the image field, can change their position, without the object image and the component measuring mark system becoming displacedA in the image field relatively to each other and the instrument being therefore deranged. This end is attained by employing for each component measuring mark system a real`optical image, in which a dist-ant virtual mark image lying in the direction toward the object is reproduced by the same parts of the telescope which also project the objectimage. vIn consequence of this arrangement any change in the position of one of these parts infiuences the component measuring mark system and the object image in exactly the same manner and does therefore in no way alter their relative position. In order to produce the two distant virtual mark images, a collimating system and a reflecting system are located in front of the telescopes.

The collimating system may be realized by a single collimator, that'is uto say, a combination of a collective lens and a niark systemarranged in the focal plane of this lens. Such a single collimator, connected with both telescopes by means of an appropriate prism system, removes a further cause of derangement of the instrument, so

far as a change in the direction of the collimator axis produces .in fact still a dis lacement "of the component measuring mar sys; tem relatively to the object image, but always exactly the same in both image fields.

In the case of a separate collimator being provided for each telescope, a similar protection against derangement can be obtained, if the mark of the one collimator be placed on or near to the collective lens of the other,

and inversely. Both collimator axes can then only change their directions simultaneously and in exactly the same manner, so i that again only an identical displacement ot' both component measuring mark systems relatively to the object images can result.

In the annexed drawing: Figure l is the plan view of the optical parts of a stereoscopic telemeter with traveling mark. Fig. 2 is the plan view of the optical parts of a stereoscopic telemeter with fixed scale. Fig. 3 is a horizontal section through the right half of a stereoscopic telemeter with fixed scale according to Fig. 2, the left half being exactly symmetrical to the right one.

In the telemeter according toFig. 1 the two object images lie in the hindmost surfaces of the image-erecting Irism systems al b1 and a2 b2, which are rigldly connected with the oculars o1 d l and c2 d2, but are r0- tatable about their own entrance axes, so that by virtue of their eccentricity the distance between the oculars can be adapted to the'interpupillary distance. The objectives e1 and e2 of the telescopes are placed between simple reflecting prisms f1 g1 and f2 g2. The component marks'h1 andh2 in the image fields are both real images and both derived from the collimator 'L' k. To accomplish this, two small optical square prisms Z1 and Z2 are arranged, one in line with the upper and the other in line with the lower half of the collective lens k. These prisms give the object directions, proper to the left and to the right telescope, to the distant virtual mark nuages produced by the collimator halves. Measurement, as is well known, is taken by makingth stereoscopic mark travel until it lies in the same apparent depth as therobject point. well-known system m of two rotatable glass wedgesis placed between the collimator and the prism Z1. Through the micrometrilcal movement of m the distant virtual mark image of the right telescope, hence also itsV real reproduction, the component h1 of the stereoscopic mark, is shifted.

In Fig. 2 the ocular prisms 'n1 and n are optical square prisms with ridges. In their hinder surfaces, being the image planes of the oculars, the components o1 and o of the stereoscopic scale are presented by real optical images produced 1n the following way: The collimators d1 k1 and i2 k2 are united, by fxin the object 4scales i and i1 on the collective lenses k1 and k, into a double collimator, the two ax'es of which have an invariable position to one another. The two distant To thisl end a virtual images of the object scales '2 and 'i1 are brought by tWo small optical square prisms p1 and p2 into the object -direction proper to each telescope. The oculars are rendered eccentric by prisms g1 and g2 and can therefore be adjusted to the inter-pupillary distance by rotating them about the axes of the lield lenses c1 and 02.

As in the construction of Fig. 3 the optical parts of Fig. 2 are employed, this ligure needs no further explanation.

' I claim:

l. A stereoscopic telemeter comprising two telescopes, neither of which is filled with a measuring mark system, a collimating system and a reflecting prism system, thesev two systems being locatedv in front of the telescopes and adapted to produce together two distant virtual mark system images, one in the object direction of each telescope.

2. A stereoscopic telemeter comprising two telescopes, neither of which is filled With a measuring mark system, two collimators and two reflecting prisms, these four being located in front of the telescopes, each collimator consisting of a collective lens and an object mark system arranged on the collective lens of the other collimator, one collimator and one reflecting prism being adapted to produce together a distant `virtual `mark system image in the object direction of one telescope, the'other collimator and the other reflecting prism being adapted to produce together a distant Virtual mark system image in the object direction of 'the other telescope.

- ALBERT KONIG. Witnesses:

PAUL KRGER, Fnrrz SANDER. 

